The head of London's National Gallery is slowly "killing off" the institution, according Julian Spalding, a former director of Glasgow's museums.

Mr Spalding said Neil MacGregor has done a deal with Tate boss Sir Nicholas Serota so the National does not show work dated after 1900.

Painting did not stop with Van Gogh

Julian Spalding

He told BBC News Online that the "deal" meant recent works were shown at Tate Modern instead, preventing the public from seeing "a coherent collection" at the National.

Mr Spalding, who made his claims in his new book, The Poetic Museum: Reviving Historic Collections, said: "Neil is an excellent director. However he is slowly killing off the National Gallery with this cut-off date.

"Instead of collecting great paintings, all you are doing is collecting art to fill in the gaps in time."

He added that the "policy" was a "big mistake", and that it was the biggest "fundamental change" in the history of the National Gallery, which has existed for two centuries.

"Now it is in danger of being turned into an historical fossil," he said. "You are depriving the public of a full history of painting.

"Painting did not stop with Van Gogh."

Neil MacGregor is moving to the British Museum

Mr Spalding's comments echoed his recent article in the New Statesman magazine, in which he questioned the direction of the National Gallery.

Mr MacGregor defended the institution in a letter to the magazine, writing: "The National Gallery exists to do two things: to collect and present great works of art and to enable the visitor to discover the story of European painting.

"Every great European city has found it essential to divide the public collections somewhere."

He added that the National Gallery's collection, which ranges from the years 1250 to 1900, combines the same span of both the Louvre and Musée d'Orsay in Paris.

Mr MacGregor concluded: "Does anyone seriously believe these two museums are 'stifled' or dying because they have an end date to their collection?"

Mr Spalding had argued that the National Gallery in Washington contains both modern and classic painting, and said: "If the Americans can do it, why can't we?"

Mr MacGregor is leaving his post to take over at the British Museum later this year and the head of the National Portrait Gallery, Dr Charles Saumarez Smith, will replace him.